Generally, all Linux distributions needs a scheduled reboot once to stay up to date with important kernel security updates. RHN (or other distro vendors) provides Linux kernel security updates. You can apply kernel updates using yum command or apt-get command line options. After each upgrade you need to reboot the server. Ksplice service allows you to skip reboot step and apply hotfixes to kernel without rebooting the server. In this post, I will cover a quick installation of Ksplice for RHEL 5.x and try to find out if service is worth every penny.
Red Hat today released kernel updates to fix at least 15 security flaws in its core called Linux kernel. RHEL users can grab the latest updates from RHN website or by simply running yum update command. This update has been rated as having important security impact.
Red Hat issued an update version of Linux operating system core called kernel that plugs various security holes for RHEL 5.x. This update has been rated as having important security impact. All users are advised to upgrade kernel package.
On a production system it is recommended that you disable the [Ctrl]-[Alt]-[Delete] shutdown. It is configured using /etc/inittab (used by sysv-compatible init process) file. The inittab file describes which processes are started at bootup and during normal operation. You need to open this file and remove (or comment it) ctrlaltdel entry.
Ctrlaltdel specifies the process that will be executed when init receives the SIGINT signal. SIGINT is the symbolic name for the signal thrown by computer programs when a user wishes to interrupt the process, for example reboot/shutdown system using [Ctrl]-[Alt]-[Del].). This means that someone on the system console has pressed the CTRL-ALT-DEL key combination. Typically one wants to execute some sort of shutdown either to get into single-user level or to reboot the machine.
Disable CTRL+ALT+Del keys
Open /etc/inittab file, enter:
# vi /etc/inittab
Search for line that read as follows:
ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
And remove the line or comment out the above line by putting a hash mark (#) in front of it:
# ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
Save the file and exit to shell promot. Reboot system to take effect or type command:
# init q
If you are using hot swappable hard disk and created new partition using fdisk then you need to reboot Linux based system to get partition recognized. Without reboot you will NOT able to create filesystem on your newly created or modified partitions with the mke2fs command.
However with partprobe command you should able to create a new file system without rebooting the box. It is a program that informs the operating system kernel of partition table changes, by requesting that the operating system re-read the partition table.
Describes how to boot dual boot FreeBSD and Linux operating system using GNU boot loader called Grub (GRand Unified Bootloader)